591.9773 
F74b 
cop.  3 


« 

» 


■ 


UNIVERSITY  OF 

ILLINOIS  LIBRARY 
AT  URBANA-CHAMPAIGN 


Digitized  by  the  Internet  Archive 
in  2018  with  funding  from 
University  of  Illinois  Urbana-Champaign 


https://archive.org/details/biologicalinvestOOforb 


IJ713 

7f£ 

i.3 


Tilt  LIBRARY 
OF  THE 

UNIVERSITY  OF  ILLINOIS 


Illinois  State  Laboratory 

OF 

Natural  History 

■  A 

Urbana,  Illinois,  U.  S.  A.  v#;-  i  ■ 

£  * 

*  *• 

STEPHEN  A.  FORBES,  Ph.D.;  LE.D., 

Director 


BIOLOGICAL  INVESTIGATIONS  ON  THE  ILLINOIS  RIVER 

1.  THE  WORK  OF  THE  ILLINOIS  BIOLOGICAL  STATION 

l 

2.  THE  INVESTIGATION  OF  A  RIVER  SYSTEM  IN  THE 

INTEREST  OF  ITS  FISHERIES 


BY 

STEPHEN  A.  FORBES 


1910 


% 


The  person  charging  this  material  is  re¬ 
sponsible  for  its  return  to  the  library  from 
which  it  was  withdrawn  on  or  before  the 
Latest  Date  stamped  below. 

Theft,  mutilation,  and  underlining  of  books 
are  reasons  for  disciplinary  action  and  may 
result  in  dismissal  from  the  University. 

UNIVERSITY  OF  ILLINOIS  LIBRARY  AT  URBANA-CHAMPAIGN 


977 


L161  — 0-1096 


THE  WORK  OF  THE  ILLINOIS  BIOLOGICAL  STATION.* 


Under  the  conviction  that  the  present  movement  for  an  inten¬ 
sive,  scientific  study  of  local  faunas  and  floras  is  likely  to  grow, 
and  to  dominate  largely  the  work  of  many  of  our  younger  biolo¬ 
gists,  and  that  it  will  center  at  first  in  our  universities,  but  will 
come  to  require  more  or  less  independent  biological  stations  for  its 
complete  realization,  I  have  thought  that  an  outline  of  the  efforts  of 
a  few  Illinois  naturalists  to  work  this  field  in  a  systematic  manner 
might  be  of  interest  and  of  advantage,  both  positive  and  negative, 
to  the  members  of  this  Society. 

The  establishment,  on  the  Illinois  river  sixteen  years  ago,  of  a 
small  station  devoted  to  this  end  was  immediately  owing  to  the  co¬ 
incidence  of  a  circumstance  and  an  accident,  the  circumstance  being 
the  existence  of  a  natural  history  survey  of  the  state,  in  rather  slow 
and  desultory  operation  at  the  time,  and  the  accident  being-  the  shift¬ 
ing  of  certain  courses  in  zoology  at  the  University  of  Illinois  from 
one  year  to  another  in  such  a  way  as  to  leave  the  department  with 
much  less  than  the  usual  amount  of  teaching  to  do  during  the  year 
1894,  and  with  much  more  time,  consequently,  for  outside  work. 
In  view  of  these  conditions  and  others  which  it  is  not  necessary  to 
specify,  I  asked  of  the  trustees  of  the  LIniversity,  in  March,  1894, 
an  appropriation  of  fifteen  hundred  dollars  a  year,  and  a  further 
sum  of  five  hundred  dollars,  to  enable  me  to  establish  on  the  Illinois 
river  a  permanent  biological  station  for  continuous  investigation 
work  throughout  the  year ;  and  in  partial  compliance  with  this  request, 
a  sum  of  eighteen  hundred  dollars  was  made  available  for  the  pur¬ 
pose.  Two  weeks  after  this  vote,  a  station  was  actually  opened  at 
Havana  in  leased  quarters,  with  a  temporary  equipment  provided  by 
the  natural  history  survey  and  the  University  conjointly.  As  the 
university  appropriation  was  not  available  until  the  first  of  July, 
the  funds  of  the  natural  history  survey  were  drawn  upon  for  the 
establishment  of  the  work  and  for  its  maintenance  for  the  first  three 
months,  and  the  same  source  of  supply  was  resorted  to  to  meet  all 
deficits  on  station  account  up  to  July  1,  1895.  At  the  biennial  legis¬ 
lative  session  of  1895  the  Illinois  legislature  made  an  appropriation 
of  twenty-five  hundred  dollars  for  the  equipment  of  the  Illinois  Bio- 

*Read  to  the  Central  Branch  of  the  American  Society  of  Zoologists  at  Iowa 
City,  AprilJS,  1910. 


1 


9 

tmJ 


logical  Station  (under  that  designation),  and  of  three  thousand  dol¬ 
lars  per  annum  for  its  expenses.  This  legislative  appropriation  for 
expenses  was  repeated  in  1897  in  a  bill  providing  for  the  mainte¬ 
nance  of  the  natural  history  survey,  and  the  work  has  been  continued 
under  these  auspices,  and  with  approximately  these  appropriations, 
ever  since.  The  station  is  consequently  a  state  establishment,  sup¬ 
ported  wholly  from  state  appropriations,  for  purposes  of  investi¬ 
gation  only, — a  point  in  which  it  differs,  I  think,  from  everv  other 
American  station  of  aquatic  biology. 

Its  general  objects,  as  defined  by  me  in  a  formal  report  published 
in  1894,  were  to  provide  additional  facilities  and  resources  for  the 
natural  history  survey  of  the  state;  and  to  contribute  to  a  scientific 
knowledge  of  the  whole  system  of  life  existing  in  the  waters  of 
the  state,  with  a  view  to  economic  as  well  as  to  educational  appli¬ 
cations.  It  had  for  its  immediate  field  the  entire  system  of  life  in  the 
Illinois  river  and  connected  lakes  and  other  adjacent  waters;  and 
an  intention  was  expressed  to  extend  operations  as  rapidly  as  pos¬ 
sible  to  the  Mississippi  river  system,  thus  making  a  beginning  on  a 
comprehensive  work  on  the  general  subject  of  the  aquatic  life  of  the 
Mississippi  valley  in  all  its  relations,  scientific  and  economic. 

The  special  subject  upon  which  I  fixed  at  first  as  the  point  tow¬ 
ards  which  our  studies  should  tend,  was  the  effect  produced  on 
aquatic  plant  and  animal  life  by  the  periodical  overflow  and  grad¬ 
ual  recession  of  the  waters  of  great  rivers, — a  topic  chosen  es¬ 
pecially  because  it  had  never  been  studied,  and  because  it  included 
in  its  scope  nearly  everything  concerning  the  life  of  our  waters  of 
any  considerable  interest  either  to  the  biologist  or  to  the  practical 
man.  As  another  result  of  our  work  I  hoped  that  we  should  ac¬ 
cumulate  material  for  a  comparison  of  the  chemical  and  biological 
conditions  of  the  waters  of  the  Illinois  river  at  that  time  and  after 
the  opening  of  the  Chicago  drainage  canal,  then  in  process  of  con¬ 
struction. 

The  main  features  of  the  equipment  provided,  were  a  floating 
biological  laboratory,  built  especially  for  the  purpose  in  1895,  a 
steam  launch,  a  number  of  skiffs,  a  variety  of  seines,  pound-nets,  dip- 
nets,  and  other  fishing  apparatus,  a  plankton  equipment,  including 
a  centrifuge  for  the  rapid  condensation  of  the  minute  contents  of  the 
collections,  and  a  set  of  breeding-cages  of  special  construction  for 
keeping  aquatic  insects  under  natural  conditions  but  exposed  to  con¬ 
tinuous  observation.  The  laboratory  boat  was  amply  provided  with 
microscopes,  chemicals,  glassware,  aquaria,  and  apparatus  and  ma- 


3 


terials  for  the  preservation  of  specimens  and  for  ordinary  micro¬ 
scopic  technic.  It  was  equipped  with  tables  and  other  essentials 
for  fifteen  workers  in  addition  to  the  station  staff.  It  proved  to  be 
admirably  adapted  to  its  objects,  being  as  comfortable  and  satisfac¬ 
tory  a  workroom  for  the  investigator  as  were  the  regular  labora¬ 
tories  of  the  University.  It  had,  for  our  purposes,  the  very  great 
advantage  of  a  thoroughly  portable  character,  and  it  was  repeatedly 
moved  from  place  to  place  at  Havana,  and  established  for  months 
at  a  time  at  various  other  points  on  the  river. 

Beginning  in  April,  1894,  the  work  continued  at  Havana  until 
April,  1899  (five  years),  at  which  time  it  was  transferred  to  Mere- 
dosia,  about  forty-five  miles  down  the  Illinois.  Here  it  remained 
until  June,  1901  (two  years  and  two  months),  when  it  was  moved 
up  the  Illinois  a  hundred  and  sixty-five  miles  to  Ottawa,  the  high¬ 
est  point  on  the  river  which  it  was  possible  to  reach  with  our  equip¬ 
ment.  After  a  year  and  five  months  at  Ottawa,  the  station  equip¬ 
ment  was  transferred  early  in  November,  1902,  to  Peoria  for  the 
winter,  and  in  May,  1903,  it  was  removed  to  Henry,  thirty-three 
miles  above. 

After  the  organization  of  the  Station,  the  survey  of  its  field, 
and  the  selection  of  substations  for  continuous  work,  it  remained  in 
charge  of  Professor  Frank  Smith  for  the  first  fifteen  months,  after 
which  Dr.  C.  A.  Kofoid  was  made  its  superintendent.  Resigning 
to  take  effect  December  31,  1900,  Dr.  Kofoid  was  succeeded  by  Mr. 
Thomas  Large,  who  was  in  charge  until  the  fall  of  1902,  and  he  was 
followed  by  Mr.  R.  E.  Richardson  in  1903. 

By  the  fall  of  1903,  after  more  than  nine  years  of  active  opera¬ 
tion,  our  accumulations  had  so  far  outrun  our  systematic  studies 
that  a  change  of  program  was  imperative;  and  the  equipment  was 
laid  up  at  Henry  under  a  caretaker,  where  it  remained  out  of  use, 
except  as  loaned  to  the  Chicago  Drainage  Commission,  until  the  sum¬ 
mer  of  1909.  You  all  remember  the  Lincoln  story  of  the  Sangamon 
river  steamboat,  which  could  make  steam  enough  to  run  if  it  didn’t 
whistle,  but  could  only  whistle  by  ceasing  to  run.  Our  biological 
station  has  found  itself,  from  time  to  time,  in  a  similar  predica¬ 
ment.  It  has  not  had  money  enough  to  maintain  active  operations 
in  the  field  and  to  prepare  and  publish  papers  and  reports  at  the 
same  time.  So,  after  a  nine  years’  run,  it  beg*an  to  whistle,  and 
now,  having  blown  its  three  long*  blasts — two  on  the  plankton  collec¬ 
tions  and  one  on  the  fishes  of  the  state — it  has  been  running  again 
since  last  July. 


4 


The  field  work  of  the  first  two  years  was  comprehensive  of  all 
aquatic  forms  and  situations,  including  plankton  collections,  quan¬ 
titative  as  well  as  qualitative,  shore  and  marginal  collections  of 
mollusks,  insects,  and  crustaceans,  dredgings  from  the  bottom  at 
various  depths,  and  collections  of  fishes  and  other  vertebrates,  by 
means  of  various  kinds  of  apparatus.  The  next  three  years  were 
mainly  devoted  to  plankton  work  in  the  Havana  district,  and  the 
last  four,  spent  mainly  at  Meredosia,  Ottawa,  and  Henry,  to  work 
on  the  fishes  of  the  Illinois  system.  During  our  period  of  active 
operation,  approximately  six  thousand  collections  were  made  in  all, 
of  which  five  hundred  were  fishes  and  two  thousand  were  plankton 
collections,  the  remaining  thirty-five  hundred  consisting  of  insects, 
mollusks,  and  a  general  variety  of  aquatic  and  subaquatic  forms.  Six 
hundred  and  forty  of  the  plankton  collections  were  made  at  Ha¬ 
vana  by  strict  quantitative  methods,  and  were  thus  available  for  a 
comparative  study  of  the  product  of  various  waters  at  all  times  of 
the  year.  Two  hundred  and  thirty-five  of  these  were  from  the  main 
stream  and  four  hundred  and  five  from  other  stations  adjacent. 

Besides  our  purely  biological  work,  weekly  samples  of  waters 
were  regularly  examined  by  chemical  methods  for  three  and  a  half 
years,  under  an  arrangement  with  the  Water  Survey  of  the  state, 
established  in  1895. 

I  can  not  attempt,  in  this  rapid  outline,  to  present  even  in  brief¬ 
est  summary  the  results  of  this  work,  but  may  be  permitted  to  ab¬ 
stract  a  few  general  statements  from  its  two  most  important  publi¬ 
cations — the  report  on  the  fishes  of  the  state  and  that  on  the  plank¬ 
ton  collections,  the  former  prepared  by  Mr.  Richardson  and  myself, 
and  the  latter  by  Dr.  Kofoid. 

From  our  fish  collections  it  appears  that  the  Illinois  basin  is  thor¬ 
oughly  representative  of  the  state  at  large.  Of  the  hundred  and  fifty 
species  of  Illinois  fishes  known  to  us,  a  hundred  and  twenty-eight  oc¬ 
cur  in  the  Illinois  or  its  tributaries.  Of  the  twenty-three  species  not 
found  by  us  in  that  basin,  eight  are  excluded  by  their  definitely  south¬ 
ern  range,  six  by  their  distinctly  northern  distribution,  and  four  are 
as  definitely  western,  while  the  five  remaining  are  so  rare  in  Illinois 
that  they  appear  in  any  of  our  waters  only  by  an  unusual  chance. 
About  three  dozen  of  the  hundred  and  twenty-eight  species  in  the 
Illinois  basin  have  a  marketable  value  as  food.  A  dozen  of  the 
best  species  are  of  really  good  quality,  and  half  of  these  are  among 
the  best  freshwater  fishes  in  the  country. 

From  our  plankton  studies  it  appeared  that  the  average  ratio 
of  plankton  organisms  to  the  water  of  the  main  stream,  year  in 


and  year  out,  was  2.7  parts  per  million,  and  the  total  average  amount 
of  plankton  moving  down  stream  past  Havana  reached  the  astound¬ 
ing  aggregate  of  three  hundred  and  fifty  thousand  barrels,  or  seven¬ 
ty-five  thousand  tons,  per  annum,  equal  to  eight  and  a  half  tons  per 
hour  the  year  round.  This  was  about  fifteen  times  the  total  weight 
of  the  fish  then  taken  from  the  river  each  year. 

Besides  our  plankton  studies  made  at  the  various  Havana  sta¬ 
tions,  each  representative  of  a  characteristic  aquatic  situation,  a 
beginning  has  been  made  in  a  study  of  the  system  of  the  entire 
stream,  taken  as  a  single  unit  of  environment.  For  this  purpose, 
trips  by  steamboat  were  made  for  considerable  distances,  with  con¬ 
tinuous  plankton  collections  throughout  each  trip.  Longitudinal  bio¬ 
logical  sections  of  the  stream  were  thus  made,  aggregating  four 
hundred  and  fifty  miles  for  the  Illinois  river  and  three  hundred  and 
sixteen  miles  for  the  Mississippi,  from  St.  Louis  to  Quincy  and  re¬ 
turn.  On  the  first  trip,  made  in  May,  1899,  an  iron  pipe  delivered 
a  continuous  stream  of  water  into  a  plankton-net  which  was  lifted 
and  emptied  every  twelve  miles.  In  all  the  other  trips  a  steam 
pump  was  used  to  supply  a  continuous  current,  which  was  passed 
through  a  meter,  enabling  us  to  determine  precisely  the  amount  of 
water  strained. 

By  such  studies  one  gets  a  vivid  idea  of  the  individuality  of  the 
river  as  an  organism,  and  of  the  complexity  of  its  structure  and  the 
sensitiveness  of  its  physiological  reactions.  A  stream  like  the  Illi¬ 
nois,  with  its  flowing  current,  varying  in  rate  in  different  parts  of  its 
course,  variously  fed  by  streams,  by  lakes,  by  marshes,  and  by  under¬ 
ground  springs,  temporarily  influenced  and  often  profoundly  af¬ 
fected  by  local  storms,  by  drouth,  by  floods,  is  a  very  different  sub¬ 
ject  of  study  from  a  lake,  and  to  me  a  far  more  interesting  one.  A 
lake  is  sessile,  simple,  stolid,  coelenterate ;  a  river  is  motile,  com¬ 
plex,  sensitive,  and  articulate :  a  lake  has  an  aspect,  a  constitution ; 
but  a  river  has  a  character,  a  behavior.  The  river  has  also  a  spe¬ 
cial  attraction  to  the  student  of  biology  in  that  it  is  more  readily 
analyzable  than  a  lake,  into  distinct  and  largely  independent  sec¬ 
tions  or  situations  which  can  be  studied  separately  and  as  a  series. 

For  a  discussion  of  our  data  of  continuous  collection,  we  have 
divided  the  Illinois  from  Hennepin  to  its  mouth,  the  part  patrolled 
by  us,  into  six  sections,  each  with  its  well-marked  individuality. 
The  slope  of  the  bed,  the  extent  and  nature  of  the  bottom-land 
waters  feeding  the  main  stream,  the  size,  length,  and  number  of  its 
tributaries,  and  the  contributions  of  sewage  waste  from  towns  upon 


6 


its  banks,  are  the  principal  causes  of  differentiation  in  different  parts 
of  its  course, — differences  which  express  themselves  most  vividly  in 
the  amount  and  character  of  the  plankton,  but  which  are  reflected 
also  more  or  less  definitely  in  the  general  aspect  of  its  biology. 

Since  last  July  our  work  has  been  carried  forward  under  the 
immediate  charge  of  Mr.  R.  E.  Richardson.  It  has  been  mainly 
directed  to  a  comparison  of  present  conditions  with  those  of  the 
period  preceding  the  opening  of  the  drainage  canal,  and  to  the  col¬ 
lection  of  materials  for  a  fuller  study  of  the  food  of  fishes  than  has 
hitherto  been  made  and  for  a  comparative  study  of  the  contents  and  the 
physical  and  chemical  condition  of  the  bottom  in  several  selected 
situations,  as  related  to  differences  in  the  plankton  and  other  bio¬ 
logical  products.  From  weekly  collections,  begun  August  20  and 
continued  for  four  months,  we  learned  that  the  yield  of  plankton 
in  the  main  stream  per  cubic  meter  was  then,  at  Havana,  approximately 
double  that  of  our  earlier  period,  notwithstanding  the  fact  that  the 
water-level  is  about  three  feet  higher  on  an  average  than  it  was 
before  the  opening  of  the  drainage  canal. 

Our  main  objects  for  the  coming  two  or  three  years  will  be  to 
complete  a  comparison  of  present  conditions  with  those  of  the  former 
time ;  to  study  the  river  as  a  unit  with  reference  particularly  to  its 
economic  values,  its  protection,  and  its  improvement ;  to  work  out 
the  details  of  its  biological  regimen  by  a  study  of  the  influence  of 
the  various  conditions  affecting  the  course  of  events  in  various  sit¬ 
uations  ;  and  to  carry  out  comparative  studies  between  the  Illinois, 
the  Mississippi,  and  the  Missouri — all  readily  accessible  from  our 
location  and  by  means  of  our  equipment.  It  is  a  large,  a  fruitful, 
and  an  important  field  of  research,  and  we  invite  the  cooperation  of  all 
so  situated  as  to  contribute  to  our  knowledge  of  any  part  of  it; 
and  to  this  end  investigators  will  be  admitted  to  our  Havana  station 
at  any  time  after  June  1. 


i 


THE  INVESTIGATION  OF  A  RIVER  SYSTEM  IN  THE  IN¬ 
TEREST  OF  ITS  FISHERIES.* 

We  have  in  Illinois  a  river  of  the  same  name  as  the  state,  which 
is  in  many  ways  one  of  the  most  remarkable  streams  in  the  country, 
and  in  no  respect  is  it  more  remarkable  than  in  its  natural  adapta¬ 
tion  to  the  breeding  and  maintenance  of  a  large  and  varied  popula¬ 
tion  of  fishes  and  other  useful  aquatic  animals;  in  none  has  it  made 
a  more  remarkable  record  than  in  the  supply  of  fish  food  which  it 
has  produced  and  is  now  producing — not  for  Illinois  only,  but 
for  the  country  at  large,  sending  out  of  the  state,  as  it  does,  and 
mainly  into  eastern  cities,  much  the  largest  part  of  its  catch.  The 
annual  yield  of  the  Illinois  river  in  fishes  only  is  over  twenty-four 
million  pounds,  worth  at  wholesale  about  $738,000.  If  this  annual 
output  were  turned  into  silver  dollars,  and  these  were  placed  in  a 
row,  equidistant  from  each  other,  along  one  of  the  banks  of  the 
stream,  there  would  be  a  dollar  every  year  for  every  two  feet  of  the 
river’s  course  from  its  origin  to  its  mouth. 

Furthermore,  we  have  no  reason  to  suppose  that  this  stream  and 
its  adjacent  waters  have  yet  reached  their  limit  of  economic  yield. 
The  effect  produced  on  them  by  the  opening  of  the  drainage  canal 
from  Chicago,  and  the  still  greater  effect  due  to  the  introduction  of 
the  European  carp,  are  examples  of  the  fact  that  the  original  con¬ 
dition  of  the  stream  may  be  largely  changed  for  the  better,  and  give 
us  reason  to  believe  that  it  may  be  made  a  still  more  important  as¬ 
set  than  now,  both  for  the  people  of  the  state  and  for  the  general 
public  who  are  the  chief  consumers  of  its  product.  Evidently  this 
is  one  of  the  natural  resources  of  the  state  and  country  which  should 
be  carefully  safeguarded.  A  thoroughgoing,  practical  investigation 
of  this  stream  is  now  especially  imperative  because  of  the  great 
changes  in  progress  at  the  present  time  in  its  environment  and  the 
still  greater  changes  contemplated  or  impending,  which  have  affected, 
or  must  certainly  affect,  greatly  and  permanently,  its  value  for  the 
purposes  which  it  now  serves.  Reclamation  projects,  for  the  pro¬ 
tection,  drainage,  and  cultivation  of  its  bottom-lands;  manufactur¬ 
ing  projects,  threatening  a  various  contamination  of  its  waters;  ca¬ 
nalization  projects  and  projects  for  the  control  and  equalization  of 
its  flow,  in  the  interests  of  transportation, — all  are  being  earnestly 
agitated,  and  several  of  them  are  in  process  of  active  execution. 

*Read  before  the  American  Fisheries  Society,  New  York  City,  September 
28,  1910. 


8 


Although  the  problem  of  the  maintenance  and  development  of 
favorable  conditions  in  this  stream  is  by  these  facts  made  somewhat 
special,  in  many  of  its  general  features  the  Illinois  is  virtually  like 
all  other  rivers,  and  a  satisfactory  program  for  its  investigation 
would  be  readily  adaptable,  I  believe,  to  many  other  streams,  and 
applicable  in  its  main  features  to  rivers  in  general.  It  is  for  these 
reasons  especially  that  I  have  ventured  to  ask  the  attention  of  this 
broadly  representative  body  to  my  special  topic,  and  to  ask  your 
criticism  of  its  proposals  now,  when  criticism  can  be  made  most 
profitable. 

Versed  as  you  are  in  the  literature  and  accepted  methods  of  fish- 
culture,  I  scarcely  need  remind  you  that  principles  of  management 
and  methods  of  protection  and  improvement  are  not  nearly  so  well 
settled  for  the  fisheries  of  our  natural  waters  as  they  are  for  fish- 
culture  in  artificial  ponds,  and  that  the  maintenance  and  utilization 
of  our  fisheries  has  been  much  less  thoroughly  studied  for  rivers, 
either  in  this  country  or  in  the  Old  World,  than  it  has  for  lakes. 
This  is,  no  doubt,  in  part  because  lake  fisheries  are,  generally  speak¬ 
ing,  both  more  important  and  more  readily  controllable  than  river 
fisheries,  and  partly  because  the  river  problem  is  much  the  more 
complicated  and  difficult  of  the  two.  The  Illinois  river  has,  how¬ 
ever,  so  many  lakes  in  its  bottom-lands,  merged  with  it  in  times  of 
flood,  distinguished  from  it  successively  with  the  retreat  of  the 
overflow,  but  connected  with  it  and  contributing  to  it  at  its  lowest 
levels,  and  the  river  itself  has,  as  a  home  for  fishes,  so  many  of  the 
characteristics  of  a  lake,  that  its  problems,  although  complex  and 
difficult,  do  not  compare  unfavorably  in  importance  with  those  of 
any  lake  in  the  world  of  equal  area.  Its  average  fall  through  the 
lower  four-fifths  of  its  course  is  only  i%  inches  per  mile,  and 
there  are  stretches  of  several  miles  throughout  which  its  fall  per 
mile  is  only  about  a  quarter  of  an  inch.  Its  current  at  low  water, 
as  it  swings  from  side  to  side  of  its  broad  and  level  flood-plain,  is 
as  slow,  at  the  dams,  as  half  a  mile  per  hour,  and  although  the  mid¬ 
stream  flow  at  high  water  is  of  course  much  stronger,  there  are 
even  then  extensive  backwater  shallows  in  which  a  fish  could  hardly 
tell  whether  it  was  swimming  upstream  or  down. 

It  is  one  of  the  most  interesting  features  of  our  field  of  opera¬ 
tion  that  we  are  able  to  bring  easily  into  comparison  the  system  of 
life  in  this  sluggish,  lake-like  stream  with  that  of  the  swift  Missis¬ 
sippi,  into  which  it  flows,  or  that  of  the  still  swifter  Missouri,  whose 
mouth  is  only  twenty-four  miles  from  its  own.  Even  the  Ohio,  very 


9 


different  physically  and  biologically  from  either  of  the  other  three, 
is  not  beyond  our  reach,  and  comparative  studies  of  all  these  streams 
have  been  begun  by  us  this  year.* 

In  such  an  investigation  as  is  here  proposed,  the  foundation  in¬ 
quiry  which  must  fix  our  beginning'  points  and  show  where  the  prin¬ 
cipal  emphasis  should  at  first  be  placed,  is  this:  Just  what  is  it  that 
we  need  to  know  in  order  that  we  may  be  in  a  position  to  do  all 
that  we  might  hope  to  accomplish,  and  ought  to  undertake,  for  the 
conservation  and  increase  of  our  aquatic  resources?  To  this  in¬ 
quiry  I  must  make,  at  first,  a  general  and  perhaps  a  disappointing 
answer.  It  is  perfectly  evident  that  if  we  wish  to  maintain  or  to 
improve  the  conditions  of  life  for  the  fishes  of  our  rivers,  we  must 
first  know  what  the  present  conditions  are,  and  which  of  these  are 
the  most  important  to  our  purpose.  We  might,  it  is  true,  hatch 
young  fish  by  the  million,  and  throw  them  out  by  the  hundred  thou¬ 
sand,  into  all  the  sorts  of  waters  which  their  species  inhabit,  without 
any  precise  knowledge  on  cur  part  of  the  conditions  in  which  they 
will  find  themselves  when  set  free,  or  any  rational  judgment  of  the 
chance  that  they  can  survive  to  adult  size.  This  sort  of  thing,  1 
surmise,  has  sometimes  been  done,  but  I  hope  that  it  is,  at  any  rate, 
done  no  longer,  and  certainly  it  can  no  longer  be  defended  as  either 
scientific  or  practical ;  it  is  simply  ignorant.  Intelligent  plans  for 
their  improvement  require  that  we  should  know  the  conditions  under 
which  our  fishes  live,  and  that  we  should  be  able  to  distinguish  bene¬ 
ficial  conditions  from  injurious,  and  important  conditions  from  un¬ 
important.  We  need  to  know  what  our  fishes  require  in  respect  to 
the  main  essentials  of  their  well-being — that  is,  to  a  suitable  water 
supply,  to  oxygen  for  respiration,  to  temperature  in  the  different  parts 
of  the  year,  to  their  food  at  all  their  ages,  to  breeding  places,  to 
freedom  of  migration  and  other  necessary  movements  to  and  fro,  and 
to  freedom  from  injurious  physical  conditions,  from  poisonous  gases 
and  solutions,  from  parasites,  from  diseases,  from  excessive  com¬ 
petition,  especially  for  food,  and  from  decimation  by  their  enemies 

It  is  commonly  conceded  I  think,  both  by  scientific  students  and 
by  practical  fishermen,  that  the  most  general  and  rigorous  limita¬ 
tions  upon  the  numbers  of  fishes  are  those  set  by  their  breeding 

*Plankton  collections,  continuous  for  all  practical  purposes,  have  now  been 
made  from  the  main  streams  of  these  great  rivers,  aggregating-  1010  miles  for 
the  Illinois,  1195  miles  for  the  Mississippi,  and  46  miles  for  the  Ohio.  On  the 
Illinois  river  these  collections  were  made,  for  ninety  miles,  from  the  station 
launch;  but  for  the  remainder  of  this  Illinois  work,  and  for  all  that  on  the  Mis¬ 
sissippi  and  the  Ohio,  we  have  had  the  use  of  the  steamer  “Illinois,”  kindly 
placed  at  our  disposal  for  this  purpose  by  the  State  Fish  Commission. 


grounds  and  their  food  supply,  and  that  of  these  the  latter  is  the 
most  important.  We  especially  need  to  know,  therefore,  what  the 
more  valuable  fishes  feed  upon  as  fry,  as  young,  and  when  full  grown, 
under  various  conditions,  and  at  different  times  of  the  year;  where 
their  food  supply  is  most  abundant;  whether  their  most  important 
food  resources  are  at  all  times  sufficiently  accessible  to  them,  and 
under  sufficiently  favorable  conditions ;  what  their  food  species  feed 
upon  in  turn;  and  so  on  down  through  the  series  of  forms  de¬ 
pendent  one  upon  another  until  we  reach  the  primary  sources  of  their 
food,  and  the  conditions  of  its  greatest  abundance  and  availability. 
Next  we  need  to  know,  for  each  important  fish,  its  spawning  times 
and  places ;  where  such  places  are  to  be  found ;  whether  the  fry  can 
escape  from  them  in  clue  season,  and  if  not,  why  not,  and  what  can 
be  done  about  it;  whether  such  most  desirable  spawning  grounds 
are  present  in  the  necessary  abundance  and  of  convenient  access,  and 
if  not,  what  can  be  done  about  that.  All  this  involves,  as  it  seems 
to  me,  a  systematic  survey  and  description,  from  the  fisheries  stand¬ 
point,  of  the  whole  congeries  of  waters — main  river,  tributary  streams, 
and  connected  lakes — so  made  as  to  lead  to  a  clear  discrimination 
of  their  individual  features  as  homes  for  fishes  or  places  of  oc¬ 
casional  resort,  and  leading  also  to  a  classification  of  them  in  definite 
groups  and  kinds,  each  kind  containing  similar  waters  with  simi¬ 
lar  surroundings.  As  soon,  however,  as  we  attempt  to  analyze,  in 
this  sense,  the  environment  and  the  needs  of  the  more  important 
fishes,  we  find  the  essential  elements  of  their  welfare  so  interwoven, 
in  one  direction  or  another,  with  those  of  virtually  all  the  other  or¬ 
ganisms  in  their  neighborhood,  and  determined  at  so  many  points 
and  in  so  many  ways  by  the  whole  local  system  of  things — biolog¬ 
ical,  chemical,  and  physical,  aquatic  and  terrestrial,  climatic  and  sea¬ 
sonal — that  there  is  evidently  no  fit  way  to  our  end  except  by  a 
general  survey  and  analysis  of  that  system  as  a  whole. 

My  proposed  program  of  investigation  begins,  consequently,  with 
a  general  natural  history  survey  of  the  river  and  its  tributary  waters, 
— with  fishes,  of  course,  in  the  lead,  where  they  belong-  biologically 
as  well  as  economically,  since  in  them  all  the  life  of  the  waters  cul¬ 
minates  and  centers.  A  great  river  system  however,  is  a  large  and 
complicated  unit  to  handle  as  one,  and  the  Illinois  with  its  two 
hundred  and  seventy  miles  of  length  and  its  basin  of  twenty-nine 
thousand  square  miles,  proved  to  be  too  large  a  subject  for  us  to 
study  with  equal  attention  to  all  its  parts.  Such  a  river  system  may, 
however,  be  readily  analyzed  into  an  assemblage  of  situations,  each 
situation  perhaps  many  times  repeated  in  different  parts  01  the  area. 


11 


and  a  study  of  the  river  as  a  whole  may  be  best  organized  and  pur¬ 
sued  at  first  as  a  study  of  these  typical  situations  out  of  which  the 
whole  system  is  compounded.  A  large  and  varied  group  of  such 
characteristic  features,  all  readily  accessible  from  a  single  center, 
was  found  at  Havana,  in  the  middle  section  of  the  Illinois  basin, 
and  in  that  section,  consequently,  much  the  greater  part  of  our  work 
on  the  river  has  hitherto  been  done.  There  we  have  gained,  in  the 
course  of  years,  a  fairly  exhaustive  knowledge  of  the  fishes  of  all 
descriptions  to  be  found  in  those  waters,  together  with  an  approxi¬ 
mate  knowledge  of  the  relative  abundance  of  each  in  average  years ; 
a  knowledge  of  the  preferred  haunts  and  usual  range  of  the  various 
species  of  fish,  and  some  acquaintance  with  their  annual  migration 
movements ;  a  mass  of  data  concerning  their  associations  one  with 
another  in  the  same  situation  and  at  the  same  time,  and  the  compe¬ 
titions  for  food  and  other  necessaries  which  these  associations  ex¬ 
press  ;  a  fair  acquaintance  with  both  the  average  and  the  excep¬ 
tional  food  of  many  of  the  species,  including  most  of  the  really  im¬ 
portant  kinds ;  a  considerable  body  of  information  concerning  their 
breeding  habits  and  their  spawning  times  and  places ;  an  accurate 
knowledge  of  both  the  composition  and  the  quantity  of  the  plankton 
of  our  streams  and  lakes,  obtained  by  several  years  of  systematic 
collection,  measurement,  and  enumeration ;  a  fairly  full  acquaintance 
with  the  other  animals  and  plants  of  the  area — those  which  inhabit 
the  margin,  live  on  the  bottom,  or  lie  buried  in  the  mud;  and  a  con¬ 
siderable  quantity  of  very  interesting  and  really  important  material  il¬ 
lustrating  the  effect  on  the  whole  system  of  life  of  the  Illinois  river 
produced  by  the  opening  of  the  Chicago  drainage  canal  in  1900.  We 
have  also  majde  many  studies  of  the  waters  themselves  in  respect  to 
their  physical  and  chemical  characteristics  and  peculiarities  under  vary¬ 
ing  conditions  and  at  various  seasons,  and  have  begun  similar  studies 
of  the  mud  and  other  materials  of  the  bottoms  of  lakes  and  streams. 

In  this  general  field  we  now  need  merely  to  finish  our  studies 
along  special  lines,  and  to  extend  somewhat  the  geographical  range 
of  our  detailed  survey.  We  shall  then  be  both  ready  and  free  to 
take  up  special  problems  of  immediate  economic  interest.  Indeed, 
much  has  already  been  done  by  us  on  such  practical  problems,  as  may 
be  seen  from  a  few  illustrations. 

We  learned  a  good  many  years  ago — and  this  fact  was  first  es¬ 
tablished  in  Illinois — that  virtually  all  our  young  fishes,  whatever 
their  adult  habits  may  be,  live  at  first  on  the  same  kind  of  food.  All 
which  hatch  in  like  situations  and  at  approximately  the  same  time, 
consequently,  compete  with  each  other  when  they  first  begin  to  feed. 


12 


We  have  also  learned  that  this  first  food — the  minute  plant  and  ani¬ 
mal  life  of  the  water,  called  its  plankton — is  produced  almost  wholly 
in  the  backwaters.  Although  flowing  streams  often  carry  an  enor¬ 
mous  quantity  of  it,  this  mainly  perishes  presently  in  our  great  silt¬ 
laden  rivers.  When,  as  in  very  low  water  in  midsummer,  the  con¬ 
tributions  from  the  backwaters  are  reduced  to  a  minimum,  or  per¬ 
haps  wholly  cut  off,  the  plankton  of  the  stream  also  falls  off  to 
little  or  nothing.  Left  to  itself,  indeed,  even  so  slow  a  river  as  the 
Illinois  would  virtually  empty  itself  of  plankton  in  a  little  while. 
The  fish-producing  capacity  of  the  stream  is  thus  proportionate,  other 
things  being  equal,  to  the  extent  and  fertility  of  the  backwaters  ac¬ 
cessible  from  it,  and  contributing  to  it  at  the  hatching  time  of 
fishes.  The  plankton  content  of  a  stream  at  that  time  is,  in  fact, 
an  excellent  index  to  the  productive  capacity  of  the  waters  as  a 
whole. 

These  facts  have  some  interesting  consequences,  one  of  which 
is  that  every  useless  fish  is  an  injurious  one,  since  it  competes  for 
food,  at  least  when  young,  with  the  useful  kinds.  By  a  useless 
fish,  however,  I  must  be  understood  to  mean  one  which  is  both  val¬ 
ueless  to  us  and  which  does  not  contribute  in  any  important  way  to 
the  maintenance  of  valuable  kinds. 

There  is  a  notable  harmony  between  the  time  of  highest  flood 
in  our  great  rivers,  the  spawning  time  of  the  bulk  of  our  fishes,  and 
the  climax  period  in  the  development  of  the  plankton.  All  coming 
together  or  following  one  another  in  quick  succession,  as  they  nor¬ 
mally  do,  conditions  are  as  favorable  as  possible  for  a  large  stock 
of  young  fishes.  The  longer  the  period  and  the  larger  the  scale 
of  the  spring  overflow,  the  better  is  the  prospect  for  a  heavy  annual 
contribution  to  the  population  of  the  stream.  To  this  no  doubt  is 
due  the  fact,  clearly  indicated  by  our  recent  river  work,  that  the 
plankton  product  of  the  Illinois  system  has  been  greatly  increased 
by  the  opening  of  the  drainage  canal  from  Lake  Michigan  and  the 
consequent  raising  of  the  average  level  of  the  river  by  about  three 
feet,  this  rise  of  river  level  of  course  resulting  in  a  more  wide-spread 
and  longer-continued  overflow. 

On  the  other  hand,  nothing  can  be  more  dangerous  to  the  con¬ 
tinued  productiveness  of  these  waters  than  a  shutting  of  the  river 
into  its  main  channel  and  the  drainage  of  bottom-land  lakes  for  agri¬ 
cultural  purposes.  It  is  fortunate  for  our  fisheries  when  one  of  these 
lakes  comes  into  the  possession,  or  under  the  control,  of  a  hunting 
or  fishing  club,  for  this  insures  its  maintenance.  The  time  has  come, 


13 


in  my  judgment,  when  the  state  should  consider  seriously  the  policy 
of  preserving  adequate  breeding  grounds  and  feeding  grounds  for 
our  river  fishes,  even  if  it  has  to  acquire  and  maintain  them,  since 
these  waters  are  in  imminent  danger  otherwise  of  being  practically 
depopulated. 

It  is  another  interesting  conclusion  from  our  recent  work  that 
the  enormous  outpouring  of  Chicago  sewage  into  the  upper  Illinois 
improves  rather  than  impairs  its  fitness  for  the  maintenance 
of  fishes.  The  organic  wastes  thus  emptied  into  the  stream  are  laid 
hold  of  by  bacteria  and  Protozoa ,  and  passed  up  by  successive  steps 
to  form  the  flesh  and  bones  of  fishes,  and  thus  finally  those  of  men. 
The  same  may  be  said  of  the  organic  wastes  of  the  towns  along  the 
banks  of  the  stream. 

Still  another  conclusion  of  considerable  practical  interest  may  be 
here  mentioned,  although  it  grew  out  of  our  aquatic  work  outside 
the  Illinois  basin.  One  large  section  of  the  state  of  Illinois,  com¬ 
prising  about  a  fifth  of  its  area,  is  peculiar  in  the  absence,  or  at 
least  in  the  unusual  rarity  there,  of  a  considerable  group  of  fishes 
which  are  abundant  elsewhere  in  the  state  and  elsewhere  in  the  sur¬ 
rounding  territory.  Now  this  section,  the  conditions  of  which  these 
fishes  evidently  do  not  tolerate,  is  distinguished  from  the  remainder 
of  the  state  by  its  geological  history,  and,  as  a  consequence,  by  the 
different  character  of  its  soil  and  of  its  streams.  The  soil  is  so 
finely  divided  that  its  particles  can  not  be  wholly  separated  from  the 
water,  even  by  repeated  filtering  with  the  finest  filter  papers,  and 
it  thus  remains  persistently  and  perpetually  turbid.  The  fishes  which 
seem  to  avoid  this  situation  are,  on  the  whole,  those  which  we  find 
in  other  parts  of  the  state  to  be  relatively  infrequent  in  very  muddy 
water.  The  inference  is  plain  that  it  is  the  permanently  muddy  char¬ 
acter  of  these  southern  Illinois  streams,  itself  due  to  the  geograph¬ 
ical  history  of  the  district,  which  renders  them  unfit  for  these  more 
sensitive  fishes.  Any  attempt,  consequently,  to  increase  the  number 
of  such  fishes  there  would  be  foredoomed  to  failure.  Doubtless 
there  are  many  other  instances  of  the  same  sort  to  be  found  in 
other  parts  of  the  country,  and  it  seems  possible  that  various  mys¬ 
terious  failures  of  attempts  made  to  introduce  new  fishes  are  at¬ 
tributable  to  some  such  cause,  not  taken  into  account  because  un¬ 
known. 

We  have  now  a  long-  waiting  list  of  special  practical  inquiries 
which  seem  clamoring  to  be  made.  We  need,  for  example,  to  ob¬ 
serve  most  carefully  the  European  carp,  now  undergoing  enormous 
multiplication  in  our  interior  waters ;  to  learn  the  details  and  the 


14 


variations  of  its  food  and  its  habits  under  different  conditions;  to 
study  the  bearings  and  consequences  of  its  spread  and  increase  on  the 
welfare  of  our  native  fishes,  and  on  the  whole  system  of  fresh-water 
life;  to  watch  for  evidences  of  local  over-population  by  it,  to  be  sus¬ 
pected  when  the  carp  or  its  competing  species  fall  below  the  average 
in  size  and  plumpness,  or  when  epidemic  diseases  appear  among  them ; 
to  follow  the  course  of  events  in  its  principal  spawning  grounds, 
where  our  own  observations  show  that  tremendous  losses,  amounting 
to  a  local  extermination  of  the  young,  may  occur  under  usual  condi¬ 
tions;  and  to  determine,  by  the  use  of  numbered  tags,  the  range  of 
the  wanderings  of  this  and  other  fishes,  and  especially  to  learn  how 
far  the  various  species  usually  go  from  the  places  where  they  were 
hatched.  We  have  a  rare  and  remarkable  opportunity  in  Illinois 
to  watch  the  progress  of  a  biological  revolution  as  important  to  the 
life  of  our  waters  as  was  the  Norman  invasion  to  the  life  and  his¬ 
tory  of  England.  Fortunately,  we  have  for  comparison  with  present 
and  future  conditions,  the  materials  and  records  of  several  years’ 
systematic  and  connected  work  done  on  the  Illinois  river  before 
the  opening  of  the  drainage  canal  into  Lake  Michigan,  and  when  the 
carp  was  but  just  beginning  to  make  its  presence  felt  as  a  disturber 
of  the  then  existing  order. 

I  can  not,  within  the  time  limits  of  your  program,  go  further  with 
the  development  of  this  subject,  and  I  must  content  myself  with 
these  sample  fragments  of  its  discussion.  When  the  results  of  our 
river  work  began  to  appear  several  years  ago,  a  leading  American 
zoologist  wrote  me  that  the  Illinois  promised  to  become  very  soon 
the  best  known — because  the  best  studied —  of  any  river  in  the  world, 
and  we  have  been  at  work  a  good  deal  of  the  time  since  in  an  ef¬ 
fort  to  increase  still  further  our  knowledge  of  that  stream  and  the 
public  appreciation  of  its  value.  In  the  face  of  the  gigantic  inter¬ 
ests — agricultural,  industrial,  commercial,  and  political — which  are 
now  mustering  along  its  course,  with  huge  schemes  in  hand  for 
revolutionary  operations  upon  its  channel,  its  banks,  and  its  back- 
waters,  we  feel  that  we  need  all  the  backing  and  assistance  we  can 
secure  from  those  concerned  in  the  preservation  and  development  of 
our  native  fisheries;  and  no  agency,  I  am  sure,  is  in  a  position  to 
give  us  more  effective  aid  than  this  old  and  influential  American 
Fisheries  Society.  Especially  we  shall  value  your  suggestions  both 
as  to  subjects  deserving  early  investigation,  and  also  as  to  practical 
measures  possible  and  desirable  on  the  basis  of  such  knowledge  as 
we  now  have  or  may  presently  acquire. 


* 

3- 


3 

o_ 

tn* 

£ 

<' 

(6 

>-» 

w» 

l-t 

O 

3 

a 

p 

*4 

p 

3 

P 

t-1 

o 

i-* 

o 


S'  w 

3 

C/1  P 
3 


P 
3 

O  _ 
ft  o 


si  cn 

S  ^ 

S-  o 

a  3 


w 


s: 

c  2 

S'  g- 

r*  ^ 

3"  O 
ft  3 

o*  a 

P  cn 

£  a 

£  g 

3  3 

2  a- 
5  o 

3  P 


3“ 

O 


(0 

O 


r1 

p 

p* 

A 

P 

3 

CP 


P 

«? 

f 

P 

?r 


The  valley  of  the  Illinois  from  Starved  Rock,  near  Ottawa,  Ill. 


In  Horse-shoe  Canon,  near  Ottawa,  111 


1'he  valley  of  Hie  Illinois  from  Prospect  Heights,  above  Peoria,  111. 


Characteristic  views  from  the  middle  course  of  the  Illinois  River 


Permanent  overflow  of  Illinois  River  bottoms.  In  “cut  road 
leading  into  Thompson’s  Lake. 


View  of  Flag'  Lake,  1910. 


aboratorv-boat  ami  station  launch. 


On  the  breeding-  grounds,  watching  movements  of  fish,  and  searching  for  fish  nests  and  fry. 


M ud-borer  a nd  equipment  for  collecting  and  assorting  materials  of  bottom. 


Preserving-  a  plankton  catch,  in  station  launch.  (Richardson,  naturalist ;  Allen,  fisherman  and  engineer.) 


;  •  ; 


. 


UNIVERSfTY  OF  ILLINOIS-URBANA 


3  0112  068175659 


